Thanks GB for the gift of a work on medicine, and then JH proceeds to comment at some length on various aspects contained in it.

In an article commenting on a pamphlet about the alleged decline of science in England, JH's name has frequently been taken in vain. JH writes to protest.

Asks that in JD's lectures at King's College, London, he remove an unfair and incorrect reference to JH.

Wants to ensure that a letter of JH's on the decline of science controversy is to be published in Brewster's journal.

Thanks JD for his letter [see JD's 1831-11-26].

Having now learned that the offensive article in the Edinburgh Review was by DB [see DB's 1831-12-1], JH writes in surprise that DB could have written what he did, and requests that JH's letter [see JH's 1831-11-25] be returned unpublished. JH will decide how to proceed.

Explains at some length the behavior of colored light, tying this to several articles that JH has written on the subject.

Comments on a letter from WH in which he discussed experiments WH had made on the infection of cowpox, typhoid, and scarlatina.

Has received a pamphlet from B about the apportionment of boroughs in a manner to eliminate the 'rotten' boroughs; JH critiques the pamphlet, especially its attempt at mathematical logic.

Responds to RP's concerns about the nature of light and the interpretation of some interference experiments. JH believes that the undulatory theory of light is the best supported by the experiments at this time.

Is now committed to the Cape journey, and will be occupied most of the time till then with the reduction of JH's nebulae observations. Comments on several other astronomical matters. [Letter is finished on board a steam packet on the way to Hamburg to visit JH's aunt, Caroline, dated 1832-6-9.]

Responds to JB's 1832-8-25 with comments about the optical properties of tourmaline. JH also talks about his astronomical work, including the collimator on his telescope and his double star work.

Compares in detail observations of several double stars made by several astronomers, and comments on differences; JH also describes a sighting of Biela's comet.

The observational data from FS regarding Gamma Virginis are so significant that JH begs FS to continue to observe and send JH the results. Comments on a number of other astronomical observational matters.

Gently rejects MP's offer to accompany JH to the Cape to act as JH's assistant. JH claims the voyage to be a 'pure family party of pleasure,' and if astronomy can not be well practiced at the Cape, the family may go on to India to visit the relatives of JH's wife, Margaret.

Comments on, and compares, WD's observations of several double stars with the observations of JH and other astronomers. In a postscript JH says 'The papers have told the truth for once—we sail sometime between Sept. and Dec.'

Having been provided with answers by JD to some questions by JH about color-blindness, JH now comments on them and offers some theoretical considerations.

Describes enthusiastically the journey to the Cape, the beauties of the country, and the joys of astronomical observing there.

Describes the departure of an expedition north of the Cape, as well as the pleasures of the country and the beautiful skies for observing. The delivery of mail is, however, so erratic as to be vexatious.

Thanks RJ for having helped J[ohn] Stewart, [JH's brother-in-law], to a job; offers to try to get some South African statistics for the Statistical Society, and along the way comments on South African political life. JH describes life at the Cape, and the beauties of the skies.